<template>
  <canvas
    :style="{ display: showFlg }"
    class="ec-canvas"
    :id="canvasId"
    :canvasId="canvasId"
    @touchstart="touchStart"
    @touchmove="touchMove"
    @touchend="touchEnd"
    @error="error"
  ></canvas>
</template>

<script>
import WxCanvas from './wx-canvas';

export default {
  props: {
    canvasId: {
      type: String,
      default: 'ec-canvas'
    },
    lazyLoad: {
      type: Boolean,
      default: false
    },
    disableTouch: {
      type: Boolean,
      default: false
    },
    throttleTouch: {
      type: Boolean,
      default: false
    }
  },
  computed: {
    showFlg() {
      return this.canvasId ? 'block' : 'none';
    }
  },
  // #ifdef H5
  mounted() {
    if (!this.lazyLoad) this.init();
  },
  // #endif
  // #ifndef H5
  onReady() {
    if (!this.lazyLoad) this.init();
  },
  // #endif
  methods: {
    setChart(chart) {
      this.chart = chart;
    },
    init() {
      const { canvasId } = this;
      this.ctx = wx.createCanvasContext(canvasId, this);

      this.canvas = new WxCanvas(this.ctx, canvasId);

      const query = wx.createSelectorQuery().in(this);
      query
        .select(`#${canvasId}`)
        .boundingClientRect((res) => {
          if (!res) {
            setTimeout(() => this.init(), 50);
            return;
          }

          this.$emit('onInit', {
            width: res.width,
            height: res.height
          });
        })
        .exec();

      var that = this;
      setTimeout(() => {
        // 导出canvas绘制的图片
        uni.canvasToTempFilePath(
          {
            canvasId: this.canvasId,
            success(res) {
              that.$emit('sendImg', res.tempFilePath);
            },
            fail(err) {
              // console.log(err)
            }
          },
          this
        );
      }, 1000);
    },
    canvasToTempFilePath(opt) {
      const { canvasId } = this;
      this.ctx.draw(true, () => {
        wx.canvasToTempFilePath({
          canvasId,
          ...opt
        });
      });
    },
    touchStart(e) {
      const { disableTouch, chart } = this;
      if (disableTouch || !chart || !e.mp.touches.length) return;
      const touch = e.mp.touches[0];
      chart._zr.handler.dispatch('mousedown', {
        zrX: touch.x,
        zrY: touch.y
      });
      chart._zr.handler.dispatch('mousemove', {
        zrX: touch.x,
        zrY: touch.y
      });
    },
    touchMove(e) {
      const { disableTouch, throttleTouch, chart, lastMoveTime } = this;
      if (disableTouch || !chart || !e.mp.touches.length) return;

      if (throttleTouch) {
        const currMoveTime = Date.now();
        if (currMoveTime - lastMoveTime < 240) return;
        this.lastMoveTime = currMoveTime;
      }

      const touch = e.mp.touches[0];
      chart._zr.handler.dispatch('mousemove', {
        zrX: touch.x,
        zrY: touch.y
      });
    },
    touchEnd(e) {
      const { disableTouch, chart } = this;
      if (disableTouch || !chart) return;
      const touch = e.mp.changedTouches ? e.mp.changedTouches[0] : {};
      chart._zr.handler.dispatch('mouseup', {
        zrX: touch.x,
        zrY: touch.y
      });
      chart._zr.handler.dispatch('click', {
        zrX: touch.x,
        zrY: touch.y
      });
    }
  }
};
</script>

<style>
.ec-canvas {
  width: 100%;
  height: 100%;
  flex: 1;
  position: absolute;
  left: -100vw;
}
</style>
